Comparison of observed RVS spectra (shown as black dots) with synthetic spectra (orange solid and gray dashed lines). The orange and gray spectra are reproduced with GSP-Spec and Li et al. (2022) parameters, respectively. The latter study is based on high-resolution spectroscopy (HR). The top and bottom panels are for a star that satisfies the MP filters with 0.30 dex metallicity uncertainty (Gaia DR3 927340858625174656) and for one that does not, with a large uncertainty of 0.95 dex (Gaia DR3 2682719929806900096). The parameters assumed in the syntheses are shown in the panels in the following order: T_eff, log g, [Fe/H], and [α/Fe] ([Ca/Fe] in case of HR. Our approach is to infer a new metallicity based on the orange spectrum, as not every star in the GSP-Spec catalog has a publicly available observed spectrum.